Research efforts are increasingly directed towards the development of biodegradable polymers derived from renewable agricultural resources. Polymer blends, which combine multiple polymers, offer enhanced properties such as ductility and toughness while being more cost-effective compared to the development of specialized copolymers. This study examines nine binary and four ternary blends of polylactic acid (PLA), poly(butylene succinate-co-adipate) (PBSA), and polyhydroxyalkanoate (PHA). The morphology of most blends was characterized by spherical inclusions. Binary blends with a 50/50 wt% ratio demonstrated distinctly different interactions between the bioplastics. The addition of PBSA increased both tensile elongation and impact strength. Notably, the PLA/PBSA blend with a 30/70 wt% ratio exhibited an elongation at break of 172%. In blends where PBSA constituted 30 wt%, there was an increase in impact strength, from 15% to 29% in PHA/PLA and PLA/PBSA blends, respectively. Overall, PBSA exhibited better compatibility with PLA compared to PHA. Mechanical testing of ternary blends was integrated with the binary blends' results to construct ternary diagrams. Dynamic mechanical analysis revealed that the glass transition temperatures in PBSA binary blends remained largely independent of the blend composition. Calorimetric analysis revealed a shift in crystallization behavior. This research highlights the potential of biopolyester blends in developing bioplastics with tailored mechanical properties for applications in automotive, agriculture, food packaging, and shape memory materials.

Mullite and mullite–alumina ceramics materials with dominance of the mullite phase are used in different areas of technology and materials science. Porous mullite ceramics materials can be used simultaneously as refractory heat insulators and also as materials for constructional elements. The purpose of this work was to investigate the WO₃ nanoparticle influence on the evolution of the aluminum tungstate and zircon crystalline phases in mullite ceramics due to stabilization effects caused by different microsize ZrO₂ and WO₃. The use of nano-WO₃ prevented the dissociation of zircon in the ceramic samples with magnesia-stabilized zirconia (MSZ), increased porosity by approximately 60 ± 1%, increased the intensity of the aluminum tungstate phase, decreased bulk density by approximately 1.32 ± 0.01 g/cm³, and increased thermal shock resistance by ensuring a loss of less than 5% of the elastic modulus after 10 cycles of thermal shock.

The current investigation presents porous ceramic materials prepared with cenospheres (CS) by using spark plasma sintering. The impact of sintering temperature, mould diameter (20, 30 and 50 mm) and cenosphere size on the properties of the sintered material was investigated. Shrinkage of the samples during sintering started at 900 °C. Total sample shrinkage during sintering increases with increasing temperature and decreases with increasing mould size; increasing sample sintering temperature increases the apparent density of all sample series CS 63–150 µm in a 20 mm mould from 0.97 to 2.3 g·cm⁻³ at 1050–1300 °C; in a 30 mm mould, 0.81–1.87 g·cm⁻³ at 1050–1200 °C; in 50 mm mould, 0.54–0.75 g·cm⁻³ at 1050–1150 °C; while CS 150–250 µm in a 20 mm mould is 0.93–1.96 g·cm⁻³ at 1050–1200 °C. Total porosity decreases from 61.5% to 3.9% by increasing sintering temperature from 1050 to 1250 °C, while open porosity reduces at lower temperatures, with closed porosity being highest in samples sintered at 1150 °C. When the sintering temperature increases from 1050 to 1300 °C, the compressive strength of the CS 63–150 samples produced in a 20 mm mould increases from 11 MPa to 312 MPa. These results correlate with the Rice model, which describes an exponential dependence of compressive strength on material porosity and fully dense material compressive strength.

Eggshells (ES) from the poultry industry are an abundant biowaste rich in calcium carbonate (CaCO₃) and collagen-containing eggshell membrane (ESM), yet integrated valorization of both fractions remains limited. This study presents a biorefinery approach combining ultrasound-assisted acetic acid (ACA-US) treatment for controlled demineralization and efficient separation of ESM from ES, followed by pepsin-assisted hydrolysis and stepwise ultrafiltration for recovery of collagen-derived fractions. Separated fractions were characterized using Raman spectroscopy, SEM-EDS, XRD, LC-MS, and amino acid (AA) profiling. ACA-US ensured effective removal of CaCO₃ while preserving collagen-related spectral features in ESM. Raman spectra showed intact Amide I, II, and III bands and a characteristic proline/hydroxyproline doublet, confirming preservation of native collagen structure prior to hydrolysis. SEM-EDS and XRD analyses verified CaCO₃ removal and its conversion into crystalline Ca salts with high Ca content. Following pepsin-assisted hydrolysis of isolated ESM, AA analysis revealed glycine, proline, and hydroxyproline as dominant residues. Ultrafiltration showed that the unsalted 50 kDa retentate contained the highest collagen and total AA content, followed by the 10 kDa retentate. Collagen-derived material was also detected in permeates, indicating distribution within ≥ 50 kDa and ≤ 50 kDa fractions due to partial fragmentation. Collagen recovery ranged from 1.24 to 2.87 g per 100 g ESM, while salted fractions showed reduced yields due to aggregation of non-collagenous proteins. This approach demonstrates a cleaner pathway for simultaneous recovery of mineral and protein fractions from ES waste, supporting circular bioeconomy valorization, although further optimization and safety assessment are required for practical industrial application and scale-up considerations.

The current investigation presents porous ceramic materials prepared of cenospheres prepared by spark plasma sintering. The impact of sintering temperature, mould diameter (20 and 30 mm diameter) and cenosphere size on the properties of the sintered material was investigated. Shrinkage of the samples during sintering started at 900 °C. Sample shrinkage during sintering increases with increasing temperature and decreases with increasing mould size; increasing sample sintering temperature increases the apparent density of all sample series CS 63-150 µm in 20 mm mould from 0.97 to 2.3 g·cm-3 at 1050 - 1300 °C, in 30 mm mould 0.81 - 1.87 g·cm-3 at 1050 - 1200 °C, in 50 mm mould 0.54 - 0.75 g·cm-3 at 1050 - 1150 °C, while CS 150-250 µm in 20 mm mould 0.93 - 1.96 g·cm-3 at 1050 - 1200 °C. Total porosity decreases from 61.5% to 3.9% with increasing sintering temperature from 1050 to 1250 °C, while open porosity reduces at lower temperatures, with closed porosity being highest in samples sintered at 1150 °C. When the sintering temperature increases from 1050 to 1300 °C, the compressive strength of the CS 63-150 samples produced in a 20 mm mould increases from 11 MPa to 312 MPa. These results correlate with the Rice model, which describes an exponential dependence of compressive strength on material porosity and fully dense material compressive strength.